Mongoose - 查找數組沒有任何匹配項的文檔

Question

這是我的收藏的架構：

{
    _id: {
        type: String,
        required: true,
        unique: true
    },
    translations: [{
        language: String,
        translation: String
    }]
}

如果我有一組語言["spanish", "french"] ，我如何找到Collection.translations沒有數組中至少一種語言的對象的所有文檔？

例如，應選擇此項：

{
    _id: "hello",
    translations: [{
        language: "not spanish",
        translation: "not hola"
    }]
}

但不是這些：

{
    _id: "hello",
    translations: [{
        language: "spanish",
        translation: "hola"
    }]
}
//and
{
    _id: "hello",
    translations: [{
        language: "spanish",
        translation: "hola"
    }, {
        language: "french",
        translation: "bonjour"
    }, {
        language: "not spanish",
        translation: "not hola"
    }]
}

這是我到目前為止所擁有的：

Model.findOne({
    translations: { $elemMatch: { language: ??? } }
});

Answer 1

我認為您正在尋找$nin運算符，請嘗試：

Model.findOne({
   'translations.language': { $nin: [ "spanish", "french" ] }
});